Just wanted to add that the AP Calculus exams are offered as version AB and version BC in part to allow more students to participate. How a school district sets up their calculus curriculum can vary substantially. In my day (decades ago), Calculus AB was a one-semester course and Calculus BC was a two-semester course with the AB and BC courses set up sequentially so that there was no overlap (BC picks up where AB ended). At my children's school district, Calculus AB and Calculus BC are still sequential courses with no overlap but both courses are full one-year courses.
It is possible to cover varying numbers of topics in varying depths.
Hmmm, that gives something to watch out for.
In some schools, an AP Calculus BC covers the two halves, with the first half being equivalent to AP Calculus AB.
In some schools, an AP Calculus BC covers just the second half, with the first half being covered in AP Calculus AB.
In the first case, it is definitely a mistake to take the two courses in sequence.
